A remote center compliance (RCC) device is a passive device for aiding insertion and mating maneuvers in robot machines, docking and assembly equipment. An RCC establishes motion about a remote center of compliance typically at, near or beyond the functioning end of the operator member. The RCC includes two structures concatenated or serially interconnected between the operator member and a mounting member. In one type of RCC, disclosed in U.S. Pat. No. 4,098,001, one structure includes flexure means comprised of a number of discrete elements or radial members aligned with radii from a center which is the remote center of compliance of the device. The other structure includes flexure means composed of a number of discrete elements which are parallel to each other and which also have localized motion portions.
In another type of RCC as disclosed in U.S. Pat. No. 4,155,169, the two structures each include flexure means which are generally flexible or deformable throughout. In one of the structures the flexure means are radial members arranged along radii from a center or focus, and that center typically is not coincident with the remote center of compliance of the device. In the other structure a laterally oriented member also includes flexure means which establish a second center or focus. The remote center of compliance is typically somewhere between the two centers or foci and each of the structures contributes to the rotational and the translational action of this type of RCC. Thus in this latter type of RCC both structures constitute a rotational portion, whereas in the first mentioned type of RCC the radial member portion is identified with the rotational action.
In the third type of RCC device, U.S. patent application Ser. No. 140,768, "Deformable Remote Center Compliance Device", filed Apr. 16, 1980, Thomas L. De Fazio, at least a portion of the operator means or member is deformable and provides a first motion center. There is a deformable means for supporting the operator means or member to permit rotation about a projected second center and providing in conjunction with the operator member a remote center of compliance between the first and second centers at, near, or beyond the end of the operator member.
When neither the operator nor the part with which it is to be mated is chamfered or provided with a suitable guide or lead-in, the initial locating of the operator member and part is difficult. One existing technique uses sophisticated equipment to sense when the operator member and part have met e.g. the peg has fallen slightly into the hole. Either the operator member or part may be the "peg" and the other the "hole". When the peg is rocked side to side using sophisticated force sensing and feedback equipment until the peg is fully seated in the hole. This technique carries the peg, limply, at a slight angle in the search phase with a center of compliance well above the free end of the peg. The location of the center of compliance away from the free end aids in permitting the free end of the peg to tilt and drop into the hole.